1 /* Common mmap definition for Linux implementation.
2    Copyright (C) 2017-2021 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef MMAP_INTERNAL_LINUX_H
20 #define MMAP_INTERNAL_LINUX_H 1
21 
22 #include <stdint.h>
23 
24 /* This is the minimum mmap2 unit size accept by the kernel.  An architecture
25    with multiple minimum page sizes (such as m68k) might define it as -1 and
26    thus it will queried at runtime.  */
27 #ifndef MMAP2_PAGE_UNIT
28 # define MMAP2_PAGE_UNIT 4096ULL
29 #endif
30 
31 #if MMAP2_PAGE_UNIT == -1
32 static uint64_t page_unit;
33 # define MMAP_CHECK_PAGE_UNIT()			\
34   if (page_unit == 0)				\
35     page_unit = __getpagesize ();
36 # undef MMAP2_PAGE_UNIT
37 # define MMAP2_PAGE_UNIT page_unit
38 #else
39 # define MMAP_CHECK_PAGE_UNIT()
40 #endif
41 
42 /* Do not accept offset not multiple of page size.  */
43 #define MMAP_OFF_LOW_MASK  (MMAP2_PAGE_UNIT - 1)
44 
45 /* An architecture may override this.  */
46 #ifndef MMAP_CALL
47 # define MMAP_CALL(__nr, __addr, __len, __prot, __flags, __fd, __offset) \
48   INLINE_SYSCALL_CALL (__nr, __addr, __len, __prot, __flags, __fd, __offset)
49 #endif
50 
51 #endif /* MMAP_INTERNAL_LINUX_H  */
52